I wanted a Commodore 64, of course, so when I got that grey instead of beige box it was immediately clear to me that it was not "the real thing". In retrospect, though, I am immensely grateful for my dad's choice. There being almost no software for the C16, and in particular the complete lack of games, meant that the only thing I could really do with it was to start programming with the built-in BASIC. So, I learnt that... and it did not take long until my dad stopped being the person I could ask about how to do things on a computer...
First experiencing a computer as something you program instead of something you use to run programs written by other people was one of the coolest things that could have happened to me at that time.
Later, I got a Commodore 128. I did some interesting stuff on it, for example, it is the only machine I ever really programmed in assembler. But to be honest, most its uptime was spent in the C64 mode running games.